Clutch and brake with resilient operator



Aug. 3, 1965 K. w. RANDALL 3,193,301

CLUTCH AND BRAKE WITH RESILIENT OPERATOR Original Filed Sept. 13, 1961 3Sheets-Sheet l INVENTOR. KENNETH W. RANDALL WMQZLM ATTORNEY Aug. 3, 1965K. w. RANDALL 3,198,301

CLUTCH AND BRAKE WITH RESILIENT OPERATOR Original Filed Sept. 13, 1961 5Sheets-Sheet 2 INVENTOR KENNETH W. RANDALL MQWM ATTORNEY Aug. 3, 1965 K.w. RANDALL 3,198,301

CLUTCH AND BRAKE WITH RESILIENT OPERATOR Original Filed Sept. 13, 1961 3Sheets-Sheet 3 5 INVENTOR KENNETH W. RANDALL Wax/.22..

ATTORNEY United States Patent I'Ciaim. (Cl. 192-47) This inventionrelates to brake and clutch assemblies for heavy traveling machines,such as cranes and power shovels in which such assemblies are alsoemployed for steering purposes.

An object is to produce a brake and clutch assembly of this character inwhich the operation of the brake and clutch are synchronized so that theclutch is engaged after the brake is released, there being a springdevice associated with the clutch so that it is spring urged both intoand out of operative engagement.

This application constitutes a division of my application Serial No.137,881, filed September 13, 1961.

Another object is to produce a new and improved brake and clutchassembly having the unique features of construction and operationhereinafter described.

Other objects and advantages will hereinafter appear and, for purposesof illustration and not of limitation, an embodiment of the invention isshown on the accompanying drawings, in which FIGURE 1 is a sectionalview of a portion of the frame and driving mechanism of a crawler drivenmachine, showing a portion of the brake and clutch assemblies;

FIGURE 2 is a side elevation of the clutch and brake operatingmechanism, parts being omitted for purposes of clarity;

FIGURE 3 is a top plan view partly in section of the mechanism shown inFIGURE 2;

FIGURE- 4 is a longitudinal sectional view of the mounting for the endsof the brake band and the spring device for tensioning same; and

FIGURE 5 is a longitudinalsectional view of the spring actuating devicefor clutch jaw actuation.

The illustrated embodiment of the invention comprises a brake and clutchassembly for heavy machines, such for example as crawler driven cranes,in which the vehicle is not only braked by the brake mechanism but thebrake and clutch mechanisms cooperate also forsteering. As shown inFIGURE 1 a portion of a revolving cranechassis is illustrated in which Adesignates the under frame on which is suitably mounted for rotarymovement a turntable assembly indicated at B. Rising centrally throughthe machine is a vertical propeller shaft C which is suitably powerdriven. On the lower end of the propeller shaft C is a bevel gear Dmeshing with a bevel gear E fixed to a cross propeller shaft F. Onopposite ends of the cross propeller shaft F are clutch jaws G which aremountedfor axially shifting movement to and from brake drums H whichhave recesses or pockets with which the lugs on the clutch jaw G areadapted respectively to enter. The brake drums H are fixed to shafts 1respectively and these shafts are suitably journaled in bearings carriedby the frame A. At the outer end of each shaft J is a sprocket gear Kwhich is connected to drive a crawler unit (not shown) for impartingtraveling movement to the machine as will be readily understood.

FIGURES 2 and 3 illustrate the brake band mechanisms forengaging thebrake drums Hand the mechanism for axially shifting the clutch jaws G.As shown, each brake band it is in two parts and each carries a lining11 for engagement with the respective brake drum H. Each of the brakeband parts Iii has an integral outwardly extend- Ediihfidi Patented Aug.3, 1%65 ice ing boss I2, a bolt 13 connecting these bosses with aninterposed coil spring 14 which urges the brake band parts away fromeach other. One of the brake band parts is fixed to an angle member 15to which a horizontal cushion spring 16 is connected, the oppoiste endof the spring being connected by a hook member to a rigid frame part 17.Vertical cushion springs 18 are interposed between the angle member 15and a rigid frame part 19.

On oppoiste ends of the respective brake band parts 10 are fittings 29,having respectively bifurcated ends 26% and 2% to receive anchor pins 21and 22 respectively which are carried by a bracket assembly 23. Thebracket assembly 23, particularly as shown on FIGURE 4,. comprises apair of spaced side plates 24, at. the upper end of which is a pair ofspacer plates 25 welded to the inside of the plates 24 respectively andthrough which the pin 21 extends. As shown, the bifurcated end 253a of afitting 2% is disposed between the spacer plates 25, and between thebifurcated end 24%: is disposed a bracket plate 26 which is rigidlyfastened by bolts 27 to a part of the machine frame. The bracket plate26 has a longitudinally elongated slot 2% through which the anchor pin21 extends and below the slot 28 is another longitudinally elongate slot29 through which the anchor pin 22 extends. As shown the anchor pin 22engages the bifurcated end 2% of a brake band fitting 20 and suchbifurcated end is disposed on the outside of the bracket plate 26.Outside of the bifurcated ends 20b and apertured at 33 to receive theend portions of the anchor pin 22 is a slide 30. The slide 3t), which isdisposed between the side plates24 of the bracket assembly 23, iscomposed of a pair of side plates 31 and a welded cross or bottom plate32.

Fixed to the cross plate 32 of the slide and depending therefrom is apin 34 which extends through a transverse pivot pin 35. The lower endportion of the pin 34 is threaded to receive nuts 36. Bearing againstthe pivot pin 35 is a plate 37 providing a seat for one end of acushioning means arranged on the pin 34, the opposite end of thecushioning means bearing against the plate 32. The cushioning meansconsists of a series of concavo convex compression washers 38 which arereversely arranged as shown and are relatively rigid but which willresiliently flex under heavy load conditions incident to machines, suchas cranes.

Link means 39 connects the lower portion of the bracket assembly 23 tothe outer end of a cross pin 40 which is carried by the free end portionof a rock arm 41. The rock arm 41 is'rigid with an elongate sleeve 42which is mounted for oscillating movements on a shaft 43 suitablycarried by a rigid bracket 44. Also fixed to the elongate sleeve 22 forrocking movements therewith and spaced from the rock arm 41 is agenerally triangularly shaped rock arm or bell crank 45 to which the pin40 isalso connected. Pivoted to one end of the bell crank 45 by a clevis47 .is a piston rod 45. The piston or actuating part for. the piston rod46 is disposed within an air cylinder 23 secured to the bracket 44. Airunder pressure is supplied to the cylinder 48 in any. suitable mannerwith suitable valve controls (not shown).

The arrangement is such that when air under the required pressure isadmitted to the cylinder 48, thebell crank 45 is rocked to effect a.movement of the bracket 23 in a clockwise. direction (FIGURE 2) therebyto release the brake band about the brake drum H. Rocking movement ofthe bell crank 45 in one direction is limited by an adjustable stop 4?carried by the bracket 44. The bellcrank is normallymaintainedagainstthe stop 49 by means of a coil spring 5t; which is carried by asupporting bracket 51 suitably fixed to the machine frame. The coilspring 56 is disposed within a guard or housing 52, attached to a framepart 53. The suporting bracket 51 has an upper spring seat 54 againstwhich the upper end of the coil spring abuts and from which depends aguide tube 55. A rod 56 has one end slidable in the guide and extendsthrough the spring and has at its oppoiste end a spring seat 57 againstwhich the opposite end of the spring 59 bears. On the under side of thespring seat 57 is clevis 58 pivotally connected to the adjacent end ofthe bell crank 45.

It will thus be seen that the spring 56 normally urges the bell crank 45in a counter-clockwise direction (FIG- URE 3) urging it against theadjustable stop The arrangement is such that the coil spring operates toapply the brake whereas the air cylinder and associated parts effectsrelease of the brake. Thus the coil spring 5th rocks the bracket 23 andassociated parts in a right hand direction (FIGURE 2) to apply the brakewhereas the air cylinder operates to move the bracket 23 and associatedparts to the left of the figure for releasing the brake. Manifestlyshould the air pressure fail for any reason the coil spring 50 operatesabruptly and automatically to apply the brake.

For operating the jaw clutches G, there is associated with the mechanismabove described jaw clutch operating means individual to each clutch. Asshown, an arm 59 has one end rigid with the sleeve 42 for oscillatingmovements therewith. The opposite end of this arm is connected by aspring device, generally indicated at 69, with an operating yoke unit 61so that by rocking movement of the arm 59 in one direction shifts therespective jaw clutch G into operative engagement with the hub of thebrake drum H and when the arm 59 is rocked in the opposite direction thejaw clutch is moved away from and disconnected from the recesses orpockets on the brake drum. H. The yoke unit 61 has a pair of pivotallymounted shoes 62 which engage in the annular groove Ga (FIGURE 1)forming a part of the respective jaw clutch as will be readilyunderstood by those skilled in this art.

The spring device 60 comprises a clevis 61a disposed at one end forpivotal engagement with the actuating arm 59. Rigid with the clevis 61ais an elongate tubular housing 62a closed at the opposite end by ascrewed-on end cap 63. Extending inside of the housing is a rod 64 whichhas an enlarged end portion 65 carrying a clevis 66 for attachment tothe respective operating yoke unit 61. The opposite end of the rod isscrew threaded to receive lock nuts or abutment means 67 which bearagainst a sleeve 68. A washer 69 abuts against an elongate sleeve orstop means 70 and also against the sleeve 68. A coil spring 71 bears atone end and against the opposite face of the washer 69 at one end and atthe opposite end against a second washer 72 which bears against ashoulder on the end of the enlarged end portion 65 of the rod and alsoagainst an elongate sleeve or abutment 73. The opposite end of thesleeve or abutment 73 bears against a washer 74 which in turn bearsagainst a short sleeve '75 containing a suitable packing 76.

It will be understood that the spring device 60 is such that acushioning effect takes place in either direction of movement of theoperating arm 59. Thus in actuating a jaw clutch G into operativeengagement with the recesses or pockets on the hub of the adjacent brakedrum H for driving the respective sprocket wheel K, a cushioning actionis afforded so as to snap the jaw clutch into engagement when sufficientmovement has been made to align the respective jaws. The arrangement issuch as automatically to release the jaw clutch when power is released.The brake may be released Without the jaw clutch engaging the drivemechanism but applies pressure sufficient to snap the jaw clutch intoengagement when sufiicient movement has been made for aligning the jaws.

4 This arrangement is or" importance in preventing possiblerunaway ofthe machine on a hill or incline.

From the above description it will be apparent that the brake band 10 issemi-self-energizing because of the design of the brake anchor which isslotted allowing the band to shift in relation to the direction ofrotation of the brake drum, thereby attording a dead center in eitherdirection and having a semi-zself-energizing effect in either direction.The spring arrangement 38 and associated parts are such as to impart aconstant pressure for contracting the brake band about the brake drum.

Numerous changes in details of construction, arrangement and operationmay be eltected without departing from the spirit of the inventionespecially as defined in the appended claim.

What I claim is:

A brake and clutch assembly for a heavy traveling machine, such as acrane, comprising a brake, a jaw clutch including an axially shiftabledriven jaw member, common means for actuating said brake and driven jawmember in a predetermined manner, said common means including anoscillatable sleeve, separate means to rock said sleeve respectively inone direction or the other for selectively actuating said brake anddriven jaw member, said common means including link and lever meansoperatively connected to said driven jaw member and brake respectively,said link and lever means extending to the driven jaw member comprisingan actuating arm rigid with said sleeve and extending outwardlytherefrom for oscillating movements therewith, an elongate tubularhousing, a pivotal connection between one end of said housing and saidrigid arm, a rod extending inside of said housing from the end oppositeto that connected to said rigid arm, an operating member for said drivenjaw member effective upon oscillation of said rigid arm in one directionto shift said jaw member into clutching engagement and in the oppositedirection to shift said jaw member out of clutching engagement, apivotal connection between the opposite end of said rod and saidoperating member, abutment means on the inner end portion of said rodwhich is disposed within said housing, a sleeve within said housing andin which said rod is slideable and against which one end of saidabutment means bears when said rod is moved axially in a directionoutwardly of said housing, a Washer against which said sleeve is adaptedto abut, stop means outside of said first sleeve and against which saidwasher is also adapted to bear, a helical coil spring about said rod andhearing at one end against the inner end of said washer, a shoulder onsaid rod disposed within said tubular housing and spaced axially fromsaid washer, a second washer on said rod providing a seat for theopposite end of said coil spring and abutting against said shoulder, andan abutment for limiting the movement of said second washer in adirection away from said first washer, the spring arrangement being suchthat cushioning takes place in either direction of oscillation of saidrigid actuating arm and the coil spring is compressed upon movement ofthe rod in either direction.

References Cited by the Examiner UNITED STATES PATENTS 1,315,980 9/19Morris 19217 2,139,198 12/38 Miller 192-17 2,539,545 1/51 Ljungkoll.

2,641,342 6/53 Hasbrouck 192109 X 2,804,925 9/57 Hitchock et al.

3,043,445 7/62 Holmes.

DAVID J. WILLIAMOWSKY, Primary Examiner.

